A chain of five missions established along the San Antonio River in the 18th century became the largest concentration of Catholic missions in North America. Built primarily to expand Spanish New World influence northward from Mexico, the missions also served to introduce native inhabitants into Spanish society. Four of the missions (San Jose, San Juan, Concepcion, and Espada) were originally founded in East Texas. As the East Texas missions succumbed to drought, malaria, and French incursions, however, they